Valve system for internal-combustion engines.



C. W. BAKER.

VALVE 1S-'ram PQR NTERNAL GOMBUSTION ENGINES.

APPLICATION FHJET) .TULY10,1912.

Patented Nov. 10, 1914.

1 Sary to introduce a deflecting iange on then ITE sTArns Partnr orner..

CHARLES WHITING BAKER, OE MONTCLAIR, NEW JERSEY.

VALVE SYSTEM FOB. INTERNALCOMBUS''ION ENGINES.

Specification of Letters Patent.

Original application led March 20, 1912, Serial No. 685,045. Divided and this application led July ,10,

L 1912. lSerial No. 708,574.

y Serial No. 685,045.

In, internal combustion engines as ordinarily constructed, it is customary to use puppet valves to control the inlet and eX- haust ports and to place these valves in the cylinder heads. stroke cycletype, however, the exhaust ports are placed in the barrel of the cylinder, and

opened and closed by the movement `of the piston. rl`he inlet ports may also be so placedand so governed; but it is then necespiston to direct the entering air toward the top of the cylinder and scavenge out the burned gases.

It is the object of my invention to provide i avalve system for internal combustion en-k gines vwhich shall not require the placing of" any valves in the c. linder head, nor the tor-l mation of any de ecting flange on the piston, thereby enabling the cylinder head and piston to be made of symmetrical and dome shaped form `s0 as to furnish maximum strength. I further avoidtlie use of puppetvalves and provide large and direct passages `for theentry of the scavenging air, by .using a multi-ported slide valve to control the inlet ports; and by providing means to give this` valve a variable time of closure, according to the load on the engine, I lam enabled to expand the workingiluid to low pressure before release, and thereby produce an in ternal combustion engine, Vwhich like' the steam engine, will have its highest eiliciency at partial loads.

. `My invention `is illustratedin the accompanying drawings in which- Figure ll is a vertical section throughv the cylinder of a two-stroke cycle engine embodying my improvements; Fig. 2, a horizontal section on the plane of the line 2*-2 In engines of the two of Fig. l; and Fig. 3 a side elevation Aof part of the valveshaft carrying a series of cams. Similar reference numerals indicate similar parts in t'hc several views.

Referring to thc drawings, the piston 1- is driven downward by the pressure produced by the burning of a vcharge of oil spraved through the pipe 2 into the combustion chamber formed between the piston 1 and the cylinder head 3. 'When the piston 1 travels far enough to uncover the ports i. the burned gases behind the piston escape into tlieexhaust pipe 4. As soon as thc pressure behind the piston is reduced to atmospheric, which takes place almost instantaneously, the multi-port slide valve 5 is quickly opened andl allows fresh air under the7 low pressure necessary for scavenging, to rushv from the vpipe G to which it is sup` plied byany suitable means,'through the inclined passages 7 which direct it toward the top of the cylinder, thereby driving the remaining burned gases from the previous stroke, out through the exhaustports 4. This action' continues until"'the piston reaches the end of its travel and returns to cover the exhaust ports ll, whenthe inlet valve 5 also closes and compression begins.

It is oneof the objects of my invention to reduce the necessary pressure for the scavenging air, and this I do by providing a larfearea -for the passage of the' entering air. eferring to Fig. `9. it will be seen that the slide valve 5 has. a width greater than its height, so that when the valve is opened, a large area is available for the direct flow of the air to thecylinder. Further, the valve being of the multi-portcd type, having bridges 8 between its ports adapted to cover ports 9 iii the scat on which the valve moves, only avery slight movement is nccessary'to completely Vopen or close the valve, and the prompt opening and closing necessary fois'effcctive scavenging' can be easily obtained. At the time this valve 5 is opened and closed it is under no pressure from the cylinder, and the maximum pressure against it at any time is much less than that 4on valves governing ports in the combustion space, since the piston 1 covers the inlet ports 10 during alzi those parts vof the cycle Patented Nov. 10, 19ML.v

ein n Where high pressure occurs. The valve is cooled by the fresh air passing through it at each revolution, and is protected from thel `hot 'gases inthel cylinder durin the expan g sion. stroke by the cool air poc {eted in "the` inlet passage 7 y,beyond thewvalve. l l u l'prefer to make the lseat on Whi'ch they valve 5 moves as partof the endsectionof the scavenging air supply pipe 6, `so`tl`1atyit 3 0 -canreadilj7 vbe rernoyed Afrom theclinder. Y improved^valvef"system a o've" described `'also furnishesfmeansi-whereby the full economy of the engine mayrv b e -malterially increased at partial loads. In vthe present operation .ofjinternal combustion engines of the Diesel :.type, the amount of oil sprayed into thecylin'der is regulated by the governor according to the load, but thepis'- ton ompressesacylinder full of air ,at-each compression st rolreno matter Whatlthe load.

In` some types of-.gas and gasolene enginesf .operating.0I1;;the ;four-stroke cycle, the charge Iof gas and-air drawn infis throttled atvvpartial; l1oads,1a nd While this effects the desired graduation in vamount, of Workingv fluid, .it Wastes poW'er'sinc'e the piston on the suction stroke f is Working against apartial vacuurn. -p .l My improved .valve system, here showmf makes possible the graduation of the amount of air as Well'fasthe amount .of fuel, in thefollqwingmanner; When the;^ engine is oper- Vatingatpa'rlti'al lqads,-.the closing of the in-. let yalveis delayed and the iston l,v on itsl return stroke, pushes part o the cylinder V'full vof-airf backinto the supply pipe 6.

Ccl'npressioi'i inthe cylinder, therefore, doesf ,y not `begin'-untilfvalve 5 closes or until theV inlet .ports lOLare covered bythe piston 1.1

40 -lf-the pistonl compresses only half a cylinder full of air into' the clearance space, the negative -Workof compression Will-be approximately only one-fourth as great- (since only half as much air is compressed and the pressure attained is only about half` as much): as .if a ,Whole cylinder full were compressed. vOn the vother hand, the tempera- .ture Aatta-ined i inl combustion will be higher, since' an amountof oil` suitable for half 5o loads has-only half as much air to heat as iffafullfcylinder of air had been draivnin and compressed. At the completion of the stroke, moreover, the gases will be expanded to. lowerpressure and temperature, than Wouldjhavefbeen the case had a Whole cylinderl Af1'ill,-.of y airv been compressed. Inasmuch, ',therefoie, :as the initial temperature is higher` and-the, yiinal temperature/is less, the proportion of-heat converted into power on the workingstrokewill be increased. In

order to operate'in'this .manner under most: favorable 4 conditions', however, it is-preferable to use heat'insulating materials on the cylinder head and piston, asslioWnv .in Fig.

e5 l and described y1n.` my application No.1

closing of the valvei51will be thusvaried ac-v y 13. In a tWo-strokelcycle internal combusrilassa andsecond Ato effect ignition of the charge 70 `after Ithe'insulating ,surfaces are heatedat the low "co'mpressin pressures produced when only part of a, cylinder fullof air is compressed. l

The valve gear for operating the valve 5 and Aopening and closing it at the proper times may be made ina variety of forms to suit different conditions.

'Fig 3, shows a suitable means for varying the time of closing of the valve. The valve shaft 11 carries tWov or more cams l2 which operate a lever 13 connected to the valve 5. The curvesof these several cams are such that each of them operates to open Ationybut-th'e. time duringfwhich the valve isnheld open is 4different with the diiferent cams. By sliding the-valveshaft ll length- Wise in its bear1ng s, ,any,one. of the cams may be brought intoaction, and thetime lof cording to whichfcam controls it.. .'Whatlclaim is:- l. A two-stroke cycle internal combustion engine having in the barrel of its cylinder a plurality -of vinlet ports with passages inclined toward thehead of the cylinder leading 'to said ports, .and a multi-portecilI valve for governing said passages. f 4 2. In a' two-stroke cycle-internalcombustionge'ngine havin inlet ports'inthe barrel of itscylinder an inc-lined passa-ges leadin thereto, af rectangular valve overning said passages and having'a lura ity-of narrow parellel ports withv bri ges between, and a seat for Isaid valve having lcorresponding ports vwith intermediate bridgeszadap'ted to register with those ofthe valve. f f a tion engmeljhaving. inlet ports inthe barrel of its cylinder and inclined passages leadingL thereto, a multi-ported valve governing said passages `anda multi-ported seat on which said valve rests, said seat forming part of the inlet pipe removably attached t0 115 the cylinder barrel. l 4. ln an internal combustionl engine, a

cylinder .having in the barrelA thereof3 a plurality df air inlet ports and inclined passages leading to said ports t0 direct the en! 120 tering air toward the cylinder head. an air inlet pipe communicatingwith said passages-band amulti-ported valvein an enlargement of said pipe as and for the purw posefdescribed. v v i y 125 .5. A tWo-stroke-cycle internal combustion l engine comprisinga cylinder having' in the wall thereof a plurality of inlet ports and inclined passages leading to said ports to direct the entering -towardltlie cylinder iool wall thereof a'pluralityof air inlet ports,

a plurality of exhaust ports below the inlet ports, a trunk piston adapted to uncover the exhaust ports near the end of its expansion stroke, e,y valve governing the inlet ports,

imd means to dela l the closing of said valve l at partial loads, wV ereby compression in the cylinder will not. begm until said valve 15 closes or until the inlet ports are covered by the piston.

In testimony whereof I have hereunto signed my name in the presence of two subscribing witnesses.

, CHARLES WHITING BAKER.

4 CHARLES S. JONES. 

